Eruptions of the Yellowstone volcanic system have included the two largest volcanic eruptions in North America in the past few million years; the third largest was at Long Valley in California and produced the Bishop ash bed.
On the diesel Passat, the TDI badge stands for Turbocharged Direct Injection, which isn't really all that helpful as the gasoline-powered Passat is also turbocharged and also uses direct injection. Volkswagen attempts to clear this up by calling this Passat the Passat TDI Clean Diesel.
The 2004 Touareg TDI had no DPF and there was no 2005 because it wouldn't pass emissions without one. All TDI 2009 and newer have a DPF. The 2009 and newer VW Touareg TDI V6 (Touareg2) and Audi Q7 TDI V6 also have an Adblue system. Again, see the link above for specifics on the Adblue system.For general info on the 2009-2010 VW Touareg, see 1000q: 09-10 Touareg TDI buying guide.here are 2 basic types of modern clean diesel exhaust systems on TDI. Those that use Adblue (2009+ VW Touareg TDI and Audi Q7 TDI) and those without (2006-2008 Touareg TDI and all other 2009+ TDI, some Euro engines). The larger and heavier cars with V6 engines need Adblue to meet 50 state emissions.